When to Buy Disposable

It's a question I struggle with — when should I buy disposable, and when should I buy stuff made to last?

My first impulse is always to to buy stuff made to last. That hits the right note in at least two ways. Over the long term, it ought to be cheaper, plus it ought to produce less impact on the environment, by using less resources and by taking up less landfill space. (See also: Fix Energy in Tangible Form)

Reality is more complex.

A Story About Reusable Bags

For a summer in in the late 1970s, I worked as a day camp counselor. That was when everything was being made disposable — and reacting against it was very trendy. At the day camp, kids and counselors were strongly encouraged to bring their lunches in reusable containers. (The kids got tokens as a reward for good behavior. We got our pay docked if we showed up with our stuff in brown paper bags, or if we used disposable plastic bags to hold individual items.)

Now, I understood that actual environmental impacts were only a secondary consideration. The main goal was to get the kids to think about issues like resource usage and landfill space. But containers for sack lunches seemed like an odd place to make a stand.

To my way of thinking, those brown paper bags after which the brown-bag lunch is named are a pretty sound choice both financially and ecologically. The resources required to make them are modest and largely renewable, they take up minimal space in a landfill, and they are biodegradable. That's pretty serious competition for the alternative — a reusable lunch box of some sort.

Consider a few of the possibilities. The sort of steel lunch box that workmen used to carry would require vastly more resources to construct, starting with mining iron ore. Of course, a steel lunch box might last for decades, but it would probably take decades before you'd have used as much energy making brown paper bags as you'd have spent smelting and then rolling the steel to make the lunch box.

Almost certainly worse were the cardboard-and-vinyl lunch boxes that most of the kids actually used. They were reusable, but generally only lasted a year before the vinyl cracked at the hinge points. (And they would be printed with a graphic that was dreadfully out-of-date a year later, and in any case inappropriate for a kid a year older.) The vinyl was a non-renewable resource, which was probably never recycled in practice (because of the effort needed to separate it from the cardboard). It wouldn't take as much energy to make as a steel lunch box, but enough to make many brown paper bags — probably more than the 180 paper bags that would be the break-even point, given the expected lifespan of one year.

I ended up using a nylon draw-string bag that I'd gotten for organizing small items in my backpack when I went camping. It was about the same size as a brown paper bag, was reusable, and served my purpose well. Of course, it was also made out of non-renewable resources, but it probably didn't require nearly as much energy as making a steel lunch box.

As an aside, much later I won (in a raffle) a fancy lunch container that was a big stainless steel thermos bottle, designed with stackable containers that you could pack with hot food in the morning so you would still have hot food at lunch time. I still have it and use it occasionally when I'm having that sort of lunch, but I'm rather doubtful that I'll ever use it enough times to justify the resources that must have gone into making it.

The Limits of Analysis

Part of my point here is that this sort of question is hard to answer analytically. What is the environmental impact of cutting down a forest versus operating iron and coal mines? Are the chemicals released into the water when making paper worse than those released into the air when smelting iron? How does a petrochemical plant compare to a steel foundry? And, of course, there's the issue of the unknowable future. What if you only use the steel lunch box for a year, and then start eating at the cafeteria? What if treating your vinyl lunch box with great gentleness makes it last three years?

The financial questions are a little more tractable, if only because you actually know the prices of the alternatives. If a steel lunch box costs $12 and a brown paper bag costs 2.5 cents, then the steel lunch box wins if it lasts at least 480 lunches — less than three years of school; less than two years of work. (Properly speaking, you'd want to discount the initial investment to account for the fact that you've lost the use of the whole $12 up front. But if the potential investment return is roughly equal to the inflation rate on brown paper bags, the simple calculation is close enough.) But even the financial questions founder on the unknowable future. What if you lose your lunch box? What if a bully pitches it under the wheels of a school bus? What if the actor depicted on the front gets involved in a scandal?

Without the ability to determine the answer analytically, we're inevitably reduced to answering such questions intuitively. To aid that, I've come up with a new rule of thumb:

Buy to last when most of the cost is for materials — because that's what's inevitably going to cost more in the future.

Buy disposable when most of the cost is for non-materials (the brand or the technology or the "intellectual property" embedded in the item) — because these sorts of non-materials will go on getting cheaper in the future.

You can really see this rule at play in items where there's an intellectual property premium added to a durable item. A metal lunch box printed with characters from a canceled TV show can probably be had almost for free at a salvage store or a garage sale (until the series has been canceled long enough that the item starts having some retro appeal).

If you have the data and the inclination to analyze the financial and environmental costs of the various alternatives, that's a worthy effort, especially for a major purchase such as a car. But for smaller purchases, and ones where the data to produce an analytical solution are hard to come by, this rule of thumb is a useful guide.